Aquarium



FIG. 1 is a front perspective view of an aquarium showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a top perspective view thereof with the cover member removed. 

The ornamental design for an aquarium, as shown. 